UV filter all the time or not?

We've been battling green water in our 10G freshwater tank for a couple of months. Finally got a UV filter and it did wonders! Now my question to you folks that have UV filters, do you run it all the time or only when there's an issue?

 

I think you can run it 24/7 as long as it isn’t shining in the tank

You could use foil to reflect it

 

It's an enclosed submersible one, so no light going directly into the tank

 

I ran a UV Sterilizer 24/7 on a marine tank. I haven't needed to use a UV sterilizer on my FW tanks.
IMO, save the bulb. Once the problem is eliminated pack it away until needed.

 

The green machine recommends 8hrs a day. So in one of my tanks it’s on a timer the other is 24/7 because I keep meaning to put it on a timer .

 

The green machine recommends 8hrs a day. So in one of my tanks it’s on a timer the other is 24/7 because I keep meaning to put it on a timer .

I would have to get a timer, lol. I'm terrible at timing.

 

I have only used mine occasionally when I get new fish. I have never had green water though.

 

The bulbs don't take kindly to power cycles so leave them on or leave them off. They may burn out prematurely or simply stop producing UV-C light.